Abstract : Real-time computer systems and real-time computations are defined for the purposes of this report. The design of software for real-time systems is discussed, employing the concept that all real-time systems belong to one of two types. The types are classified according to the type of control program used; namely: Pre-assigned Iterative Cycle and Real-time Queueing. The two types of real-time systems are described in general, with supplemental broad flow diagrams. Illustrative examples of each of these types are given (also with flow diagrams) using existing systems. It is indicated that time sharing is a direct extension and a member of the Type 2 Real-time Queueing program category. The recommendations emphasize the gain in system effectiveness and programmer capability when the programmer working with real-time systems extends his interest to the complete package of software, including control. (Author)